Drilling tool



Nov. 15, 1960 HANs-JoAcHiM FlNKELDl-:x 2,960,132

DRILLING TooL.

Filed Aug. 18, 1959 5 Sheets-Sheet l DRILLING TOOL 5 Sheets-Sheet 2Filed Aug. 18, 1959 FIG. 5

FIGJ:L

INVENR Nov. 15, 1960 HANS-JOACHIM FINKELDEI 2,960,132

DRILLING TOOL 3 Sheets-Sheet 3 Filed Aug. 18, 1959 FIG. l0

mm F FIG. 6

lll

United States Patent DRILLING TOOL Hans-Joachim Finkeldei, UntereLichtenplatzerstr. 80, Wuppertal-Barmen, Germany Filed Aug. 1S, 1959,Ser. N0. 834,612 1 Claim. (Cl. 145-53) The present invention relates toa drilling tool with a drilling spindle having two spiral controlgrooves disposed in opposite directions and mounted in two selectivelyusable and releasable nuts, respectively. The drilling spindle issurrounded by a protecting tube which is secured to a handgrip of thetool, the drilling movement being releasable in the complete withdrawnposition of the drilling spindle by means of a lock, whereby thedrilling head carries exchangeable taps or the like.

It is one object of the present invention to provide a drilling toolwherein the locking of the drilling spindle in its withdrawn position isachieved in such a manner that a shoulder, of a locking fork projectsinto an annular groove of the drilling spindle, said shoulder beingformed substantially as a segment of a circle and having a crosssectionforming an edge, and a locking fork freely sliding crosswise to thelongitudinal axis of the spindle in a locking nut, the annular grooveprovided on the periphery of the drilling spindle having a cross-sectionforming likewise an edge. The control of the fork is brought about bythe co-operation of a cam of the fork with a control path of a ringsurrounding the locking nut, on the one hand, and by means of the forkarms in connection with additional control curves of the ring, on theother hand.

It is another object of the present invention to provide a drilling toolwherein a ring surrounding a locking nut has at least three controlcurves or paths, one of which controls the locking cam, while the othertwo paths engage from the outside the rounded arms of the fork.

It is yet another object of the present invention to provide a drillingtool, wherein the control fork is set laterally into a slot of thelocking nut, whereby the two arms of the fork are safely guided againstrotation with the inner faces of the parallel arms of the fork on aconnecting web remaining after providing the slot.

With these and other objects in view, which will become apparent in thefollowing detailed description, the present invention will be clearlyunderstood in connection with the accompanying drawings, in which:

Figure 1 is a front elevation of a drilling tool;

Fig, 2 is an elevation of the drilling tool partly in section, withinserted drilling nuts;

Fig. 3 is an end view of the double sleeve which is slidable on thehollow shaft;

Fig, 4 is an elevation of the double sleeve mounted on the shaft, theouter sleeve being shown in section.

Fig. 5 is a front elevation of the shaft with a flat spring secured tothe locking tongues, the sleeve being removed for better showing;

Fig. 6 is an elevation of the head of the drilling tool showing a partof the hollow shaft;

Fig. 7 is a view partly in section of the locking nut with thesurrounding ring;

Fig. 8 is an end view of the locking nut with the locking fork inengaging position;

Fig. 9 is a View similar to that in Fig. 8, yet the fork being shown inreleasing position; and

Fig. 10 is a section through the locking nut and the 2,969,132 CCPatented Nov. l5, 1960 surrounding ring crosswise to the longitudinalaxis just above the fork.

Referring now to the drawings, the drilling tool 10 carries exchangeableblades, taps or the like, constituting the drilling head which isconnected with the drilling spindle 11. The latter is mounted in twodrilling nuts 12 and 13 disposed in a hollow shaft 14. The shaft 14 sitson a protecting tube 15 surrounding the drilling spindle 11 and carryingat its other end the gripping handle 16.

In accordance with the present invention, the tool drilling nuts 12 and13 which receive the drilling spindle 11 are of dilferent length and aremounted in accordance with the present invention in a double bearing.The drilling nuts 12 and 13 are supported at one portion of theirvperiphery, which is formed like a wall 18 of the hollow shaft 14, whilethe other portion 4S and 46, respectively, of the periphery of thedrilling nuts 12 and 13 is received by an axial bearing. This axialbearing is formed for the longer of the two nuts, namely for the nut 13,by a bearing 19 which is step-wise set off relative to the inner wall 18of the shaft, the nut 13 abutting the end face of a ring 20. The 'othernut 12 is received, however, by a locking nut'21 which may be screwedinto the hollow shaft 14 from its end face, by overlapping the portionof the periphery 46 of the drilling pinion 17, on the inner nut 12 whichportion has no pinion formation.

A double sleeve 22 and 23 is mounted on the hollow shaft 14, whichdouble sleeve covers completely the drilling mechanism in the shaft 14.The double sleeve 22 and 2'3 comprises substantially two tube sectionstelescoped into each other, which are secured against rotation relativeto each other in such a manner that an inwardly bent abutment tongue 24,which is disposed at the end face of the outer sleeve 23, co-operateswith a recess 25 formed complementary to the tongue 24 in the innersleeve 22.

The inner sleeve 22 is equipped on a portion of its periphery with aslot 26 which is substantially obliquely disposed to the longitudinalaxis of the inner sleeve 22, which slot 26 serves as a guide for a cam27, which in turn sits on a spring blade 29, the latter working againstthe locking tongues 2S. Upon rotation of the double sleeve changed, sothat, for instance, in one positionone of the locking tongues 28 mesheswith the pinion 17 of the nut 13, while the other of the locking tongues28 is raised, so that the pinion 17 of the latter is freely rotatable.In another position, upon rotation of the double sleeve 22 and 23 in theopposite direction, the other nut 12 is properly locked, while the nut13 is freely rotatable. AIn a median position of the spring 29, as shownin Fig, 4 of the drawings, both locking tongues 28 are in engagementwith the corresponding pinions 17. A drilling operation is not possiblein the last mentioned position 0f the spring 29, since both pinions 17of the nuts 12 and 13 are locked.

In order to secure each of the spring positions, the inner sleeve 22 hasclose to its edge preferably three recesses 30 which are disposedequally spaced apart from each other and are arranged on a common centeraxis. A spring biased ball rests in the respective recesses 30 in eachof the positions of the spring 29, which ball rests in a cavitv 31 orthe like provided in the hollow shaft 14. In order to control theadjustment of the spring 29 and the direction of movement for the drill,respectively, the outer sleeve 23 is equipped with a recessed marker 32on the one hand, and a written marker 33 on the other hand` whichco-operates with a marking on the inner sleeve 22 in correspondence withthe position of the spring 29. In this manner it is possible, forinstance, upon rotation to the right of the double sleeve 22 and 23 toobtain a right drilling motion, or a left drilling motion upon rotationof the double sleeve 22 and 2:3

22 and 23,'the position of the spring 29 may .be-

in opposite direction. In the median position of the double sleeve 22and 23, no drilling motion is obtained, since both locking tongues 28mesh with the pinions 17. The periphery of the outer sleeve 23 isprovided suitably with a knurled portion 3,4l or the. like, in ordertoobtain a better gripping face during the rotation of: the doublesleeve 22 and 23.

Iniorder to lock the drilling spindle 1'1 in. its. completely withdrawnposition, a locking fork 35 is provided, which is insertedv into thelocking nut' 21 lateraliy crosswise to the, longitudinal axis of thelocking nut 21, so thatv the locking fork 35 abuts with its fork arms`376 a web por-- tion 37 of the locking nut 2'1 which has remained duringthe: forming of the slot, the fork arms 36` receiving the web portion 37therebetweem Thecontrol of the locking fork 35 is achieved in such amanner thatva cam 38 cooperates with a guide path, 39 provided inasurrounding ringu41, which causes an advancement of the fork 35 inradial direction towards the longitudinal center of the axis. By thisarrangement', a shoulder 40 of the fork 3S, which is substantiallyformed as a segment of a circle, engages an annular groove 42 of thedrilling spindle 11, so that a reliable locking is obtained; The returnof the locking fork 35 into its releasing position is obtained by theco-operation of two additional control curves 43 and 44 in combinationwith the fork arms 36, the latter being rounded on the sides opposite tothe control curves 43 and 44, so that the fork arms 36 slide along thecurves 43v and 44 easily and without any resistance.

The shown and described embodiment of the present invention is merely anexample for the realization of the present invention and not limitedthereto, rather, within the scope of the present invention, otherembodiments and applications are possible, particularly as to thestructurev and design of the drilling nuts 12 andl 13, as well asV oftheir mounting in the shaft 14. It is` also possible to make the springadjustment by the combination of the two sleeves 22 and 23 also byother-means, whereby, however, care must be taken that the spring 29itself, or its control element, is not accessible from the outsiderather is covered by all means. The locking fork 35, as well as itscontrol, could be designed in a manner dilerent from that shown in thedescribed embodiment. It is essential, however, that the control of thefork 35 is obtained by means of cams and fork arms in connection withcontrol curved faces, since by such arrangement return means, as forinstance springs or the like, may be eliminated.

While I have disclosed one embodiment of the present invention it is tobe understood that this embodiment is given by example only and not in alimiting sense, the scope of the present invention being determined bythe objects and the claims.

I claim:

A drilling tool comprising a drilling spindle, a protection tubesurrounding said drilling spindle and a hand grip carrying saidprotection tube, said drilling spindle having two spiral control groovesdisposed in opposite directions, and being mounted in two selectivelyusable and releasable drilling nuts, locking means for stopping thedrilling movement in the completely withdrawn position of said drillingspindle, a hollow shaft and a locking nut, the latter being screwed insaid hollow shaft and connecting said drilling spindle with said shaft,and said locking means comprising a locking fork having two fork armsequipped with outer rounded faces and having a shoulder formedsubstantially as a segment of a circle and having a cross-sectionforming an edge, said drilling spindle being equipped with an annulargroove having a cross-sectionforming an edge complementary to thecrosssectionv of said shoulder, said locking fork sliding freely intosaid groove of said drilling spindle crosswise to the longitudinal axisof said drilling spindle, a ring surrounding and carried by said lockingnut, said locking fork having a cam disposed at its rear face, said ringhaving at least three inner ca m faces, a first of said cam facesco-operating withY said cam of said locking fork and a second anda thirdof said cam faces (zo-operating with said outer rounded faces of saidlocking fork, said locking nut havingV a slot disposed in a planeextending perpendicularly to the longitudinal axis of said drillingspindle and forming a web on one side of said slot and receiving saidlocking fork by lateral insertion, and said fork arms of said lockingfork having parallel inner faces which engage the end faces of said webin order to secure said lockingv fork againstrotation upon the axis ofsaid drilling spindle.

References Cited in the le of this patent UNlTED STATES PATENTS1,531,086 Fegley Mar. 24, 1925 1,578,866 Swain Mar. 30, 1926 2,667,357Andreasson Jan. 26, 1954

